How an IUI due date is calculated
IUI is timed to happen around ovulation, so the IUI date is the best estimate of the conception date. A due date is about 266 days (38 weeks) after conception:
IUI due date = IUI date + 266 days
Pregnancy weeks are still counted from an equivalent last period 14 days before the IUI, so on the day of your IUI you are counted as 2 weeks pregnant.
Trigger shots and two inseminations
Many IUI cycles use a trigger injection, after which ovulation usually follows within about a day and a half. If you had two inseminations, clinics generally date from the one closest to ovulation — ask your clinic which date they use. Differences of a day or two make little difference to the due date.
After your IUI
The two weeks between IUI and a pregnancy test can feel long. Implantation usually happens 6 to 12 days after ovulation, and hCG then needs a few days to rise, so clinics typically arrange a blood test about two weeks after the insemination. If you had a trigger injection, a home test taken too early can show a false positive from the injection itself. If the test is positive, the due date above is your estimate until your first scan confirms it.
IUI vs. IVF dating
With IVF, fertilisation happens in the lab and the embryo’s age is known, so the IVF Due Date Calculator uses the transfer date and embryo age instead. After IUI, the Pregnancy Test Calculator shows when a test is most reliable.